EMPIRICAL FORCE-FIELD (MM2 AND MM3) CALCULATIONS FOR PERACETYLATED 1-DEOXY-1-NITROHEPTITOLS AND PERACETYLATED 2-DEOXYALDOOCTOSES SUGGEST THAT THEORETICAL CONFORMATIONAL-ANALYSIS MAY BE UNRELIABLE

The conformational analysis of all sixteen possible diastereomeric con figurations of peracetylated 2-deoxyaldooctoses and peracetylated 1-de oxy-1-nitroheptitols was undertaken. Molecular mechanics calculations were used to compute the geometries and energies of the compounds. Pro ton-proton vicinal coupling constants were also estimated from molecul ar mechanics results after applying a generalized Karplus equation. Co mparison with the available experimental data confirms the global corr ectness of the calculations. A comparative study of MM2 and MM3 force fields for these compounds is presented.